IFNτ mediates chemotaxis, motility, metabolism and CK18 downregulation in bovine trophoblast cells in vitro via STAT1 and MAPK42/44 signaling

IFNτ is the ruminant pregnancy recognition signal. In the study we investigated the autocrine influence of IFNτ on bovine F3 trophoblast cells. In detail chemotaxis, motility, metabolism, cell polarisation (CK18; ezrin) and the underlying classical (STAT1) and non-classical (MAPK42/44) signaling pathways were examined. Cellular signaling was analysed by densitometric Western blot (STAT1, MAPK42/44, proteinkinase B) and RT-PCR (IFNAR1, -2). Cellular assays were carried out for chemotaxis (agarose spot assay), cell motility (live cell imaging), metabolism (MTT) and cell polarisation (CK18; ezrin). In vivo-produced conceptuses of gestational days (GD) 20–39 underwent immunohistochemistry (CK18; ezrin) to set the in vitro findings (cell polarisation) in proportion to the in vivo situation. IFNτ (10–1000 ng/ml) mediated dose-dependent effects. 10 ng/ml IFNτ induced chemotaxis and motility, whilst 1000 ng/ml led to reduced chemotaxis, motility and a 92-fold activation of MAPK44. Stimulation of cells with 10–1000 ng/ml IFNτ promoted metabolism (1.4-fold), increased the gene expression of IFNAR1/2 (24 h) and downregulated CK18 but not ezrin. All described in vitro effects were significant. Signaling, motility and metabolism could be blocked by specific inhibitors (PD98059, LY294002). CK18 and ezrin expression patterns in the trophoblast of in vivo conceptuses differed depending on GD. IFNτ is a major factor for bovine F3 trophoblast cells and mediates a variety of cellular actions ranging from chemotaxis to polarisation. IFNτ exerts its effects via classical (STAT1) and non-classical (MAPK42/44) signaling pathways in a dose-dependent way. We hypothesize that (dose-dependent) IFNτ regulation of the cellular effects could also be essential for bovine elongation and implantation. •IFNτ activates MAPK42/44, STAT1, pAKT in bovine F3 trophoblast cells.•IFNτ promotes metabolism, motility, chemotaxis and a depolarisation (CK18).•Autocrine in vitro effects of IFNτ are highly dose-dependent.•Expression of trophoblast CK18 and ezrin also change in vivo (GD 20–39).